Automatic Data Processing, Inc. (ADP), is an American provider of business outsourcing solutions. It is also a provider of computing services to automobile and heavy equipment dealers. ADP is one of four U.S. companies to get a AAA credit rating from Standard & Poor's (S&P) and Moody's.

In 1949 Henry Taub founded Automatic Payrolls, Inc. as a manual payroll processing business. In 1957, the company changed its name to Automatic Data Processing, Inc. (ADP), and began using punched card machines, check printing machines, and mainframe computers.ADP went public in 1961 with 300 clients, 125 employees and revenues of approximately $400,000.

From 1985 onward, ADP’s annual revenues exceeded the $1 billion mark, with paychecks processed for about 10% of the U.S. workforce. In the 1990s ADP began acting as a professional employer organization (PEO). Around this time, the company acquired Autonom, a German company, Kerridge Computer Co. Ltd., a dealer management systems (DMS) provider to auto dealers in the UK, and the payroll and human resource services company, GSI, headquartered in Paris.

In 2007, the ADP Brokerage Service Group was spun off to form Broadridge Financial Solutions, Inc. (NYSE: BR), removing about $2 billion from ADP's total yearly revenue.ADP was distributing one share of Broadridge common stock for every four shares of ADP common stock held by shareholders of record as of the close of business on March 23, 2007.ADP is sponsor of the ADP National Employment Report as well as the ADP Small Business Report.